Radiofrequency lesioning electrodes have common application in neurosurgery. Examples of previous designs are illustrated in the present author's Pat. No. 4411266. Typically these electrodes consist of a cylindrical shaft insulated primarily over its entire length, with the exclusion of the exposed distal tip. Thermocouple or thermistor wires were located internal to the longitudinal shaft of the electrode, and a thermocouple of thermistor sensor is located at the electrode tip. Such electrodes are extremely important in neurosurgery and have been used effectively there.
The present invention is a new and unique electrode configuration involving a catherter-type electrode for use in cardiology. In that field, an objective is to destroy portions of the nerve-carrying cardiac tissue, such as the Hiss bundle, in which irregular pulse sources are present. Also in the case of cardiac infarction where disturbance of the normal trigger patterns and flow of electricity in the cardiac tissue is altered, radiofrequency heating or other heating methods for ablation of the trouble zones is indicated. Flexible cardiac catheters are well know in the field of cardiology. These catheters in some cases are insulated over their entire length and are directed through openings in the veins in the groin and work up to the cardiac region. Once there, the exposed metal tip of the electrode can be directed to a desired portion of the cardiac wall, and a pulse or continuous amount of radiofrequency energy can be delivered so as to heat the desired tissue. Here, as in the neurosurgical context, faithful reproduction of the tissue heating is important, and also rapid response to tell the surgeon about immediate changes of tissue is also of great importance.
Therefore, one object of this invention is to implement an embodiment of the flexible cardiac catheter for the purpose of cardiac tissue ablation by radiofrequency heating with ultra-fast faithful recording of temperature in the affected tissue.